The present invention relates to a unique and novel pleated filter media arrangement and method of assembly and more particularly to a unique and novel pleated filter arrangement and assembly method which includes at least one sheet of pleated porous filter medium with unique pleat spacer inserts between adjacent pleats and a unique method of assembling the pleated filter medium with spacers therebetween.
Spacer structures between adjacent porous filter media pleats are generally well known in the fluid filtration art. These past structures include various arrangements for providing spacer inserts between sheets of pleated porous filter media, such as in U.S. patents: U.S. Pat. No. 3,344,590, issued Oct. 3, 1967 to T. R. Smith et al; U.S. Pat. No. 3,691,736, issued Sept. 19, 1972 to G. M. Neumann; U.S. Pat. No. 3,941,571, issued Mar. 2, 1976 to A. R. Getzin; U.S. Pat. No. 4,056,375, issued to W. Ringel et al on Nov. 1, 1977; U.S. Pat. No. 4,227,953, issued Oct. 14, 1980 to S. J. Wasielewski et al; U.S. Pat. No. 4,874,517, issued Oct. 17, 1989 to H. W. Esch; and, U.S. Pat. No. 5,084,178, issued Jan. 28, 1992. to J. D. Miller et al. Other prior art patents have relied upon displacements in the filter media itself rather than spacer inserts- such as can be seen in U.S. Pat. No. 5,066,400, issued on Nov. 19, 1991 to G. J. Rocklitz et al; U.S. Pat. No. 5,306,321, issued on Apr. 26, 1994 to R. J. Osendorf; and, U.S. Pat. No. 5,744,036, issued on Apr. 28, 1998 to Kyung-Ju Choi. Further, U.S. Pat. No. 5,800,585, issued Sep. 1, 1998 to Kyung-Ju Choi, teaches supporting pocket netting having sufficient stiffness and rigidity to support a preselected pocket weight per given unit area.
For the most part, the past spacing arrangements have been comparatively complex and expensive in manufacture of the several parts involved and in the assembly of such parts. Further, these past spaced arrangements have presented comparatively high resistances and concomitant pressure drops in the treated fluid stream along with reduced filtering areas in given units of space.
The present invention provides a unique and novel spacer insert arrangement for pleated filter media sheets which is economical and straightforward in manufacture and assembly, requiring a minimum of parts, allowing for a minimum of pressure drop across the filter media and optimizing the filtering surface in a given space, enhancing pleated filter media spacing and fluid stream flow therethrough. In addition, the present invention provides a unique method and apparatus which is straightforward and economical with a minimum of parts and a minimum of steps for assembling the novel filter arrangement.
Various other features of the present invention will become obvious to one skilled in the art upon reading the disclosure set forth herein.
More particularly, the present invention provides a pleated filter arrangement for removing particulate matter from a fluid stream comprising; at least one sheet of porous filter medium having opposed faces and being pleated into a plurality of longitudinally extending spaced pleats of porous filter medium; a plurality of longitudinally extending, flow-through, screen-like inserts, each insert including a body portion sized to be inserted into nesting relation with and engaging between opposed faces of adjacent pleats of porous filter medium to separate the adjacent pleats, the body portion of the inserts including spaced strands of preselectively differing cross-sectional thicknesses with at least certain of which extend in transversely crossing relation and arranged to enhance pleated filter medium spacing and particulate carrying fluid stream flow therethrough. In addition, the present invention provides a unique method of forming a pleated filter comprising: passing a flat strip of filter medium of preselected width into a pleating zone to pleat the filter medium into adjacent pleats having opposed faces of preselected depth with troughs therebetween; passing the pleated filter medium from the pleating zone into a spacer zone to insert a screen-like spacer member having spaced strands into each of the troughs with the spaced strands having differing preselected cross-sections and positioned between opposed faces of adjacent pleats to maximize fluid flow therethrough; and passing the spacer inserted pleated filter medium from the spacer insert zone to a severing zone to separate unit spacer-inserted filter medium into preselected lengths.
It is to be understood that various changes can be made by one skilled in the art in one or more of the several parts and in one or more of the several steps of the inventive arrangement and method disclosed herein without departing from the scope or spirit of the present invention. For example, the geometry of each pleat and differing spacer strands can be varied, as can the materials employed, without departing from the inventive pleated filter arrangement and method of forming the same.